Thursday, April 19, 2018
Tampa Bay Weather

Emerging El Niño raises hopes for another slow hurricane season

Hurricane forecasters are reporting signs of a developing El Niño, a weather phenomenon that can significantly suppress the number of hurricanes over the upcoming six-month Atlantic season.

"Most of the models right now are forecasting it," hurricane forecaster Phil Klotzbach said.

El Niño would be the key factor in determining hurricane activity during the season, which runs from June 1 through Nov. 30.

An El Niño occurs when warm surface waters from the western Pacific Ocean are pushed to the eastern Pacific. The warmer surface waters cause upper-atmospheric storms and shearing winds that can thwart hurricane formation thousands of miles away in the Atlantic basin — the Gulf of Mexico, Caribbean Sea and Atlantic Ocean.

Warmer surface waters are being measured by ships, buoys and satellite technology but still need a stronger push, experts say.

"We've been seeing strong westerly winds near the international date line for a few weeks, and that's usually a pretty good precursor of an El Niño event," Klotzbach said.

Preliminary signs show potential for a strong El Niño, possibly during peak hurricane season in late summer, said Jeff Masters, director of meteorology for Weather Underground.

"What we are seeing is similar to 1997, before the start of the greatest El Niño ever recorded," Masters said.

In the 1997 El Niño, it was a typhoon east of the Philippine Islands that created a burst of westerly winds, pushing the warm surface water to the east, Masters said. Only nine storms formed that year, three of them hurricanes.

El Niños, which generally occur every two to seven years, have been traced back tens of thousands of years and are considered part of the basic cycle of the Pacific Ocean. A La Niña is the opposite of El Niño, in which warm surface waters slough back to the western Pacific.

An El Niño can increase surface water temperatures a degree or two or, in extreme cases, as much as 5 or 6 degrees in areas of the eastern Pacific, especially near the equator. Such a change, even when modest, can stoke the atmosphere, causing the type of storms that can disrupt hurricane formation or push storms away from the U.S.

The National Center for Climate Prediction on Thursday issued an El Niño watch: a greater than 50 percent chance of an El Niño in the next three to six months.

At least one other key factor in hurricane formation is pointing to a possible slowdown in seasonal activity: Sea surface temperatures are slightly below normal.

"The Atlantic right now is cooler than normal, maybe just a half-degree or so, but that's significant," said Klotzbach, who, along with veteran hurricane forecaster William Gray, will issue annual seasonal predictions in early April.

The reality is that neither El Niño nor cooler sea surface temperatures are a guarantee against disaster.

Some of the most destructive storms in history occurred during El Niño years. In 2004, four strong hurricanes hit Florida in what was considered a weak El Niño.

And forecasters acknowledge that early season forecasts are not always spot-on.

Most major forecasters badly erred in last year's seasonal projections, predicting on average about 17 named storms, half of them hurricanes and half of those major hurricanes with winds of 130 mph or more.

The season produced only two hurricanes. Neither of them were major storms.

What's more, accumulated cyclonic energy — a measure of the total amount of tropical energy in the Atlantic basin — was about a fourth of the norm.

Comments
Forecast: Scattered showers could dampen weekend plans across Tampa Bay

Forecast: Scattered showers could dampen weekend plans across Tampa Bay

Scattered showers and thunderstorms could pester Tampa Bay throughout the weekend, culminating in a peak chance of rain early next week.A small cold front will meander over the bay area by Friday afternoon but should have little affect on the area, t...
Published: 04/20/18
Forecast: Clear skies for Tampa Bay lead to a hot, humid and rainy weekend

Forecast: Clear skies for Tampa Bay lead to a hot, humid and rainy weekend

Expect warm weather, clear skies and a slight increase in humidity across Tampa Bay in the next few days, before an incoming cold front raises the chance for rain.Temperatures this morning are in the low 60s with a little bit of damp air. The dry air...
Published: 04/19/18
Forecast: Warm weather continues for Tampa Bay, but humidity and clouds are returning

Forecast: Warm weather continues for Tampa Bay, but humidity and clouds are returning

The temporary cool weather has come to an end as temperatures rise back up to the lower 80s by Wednesday afternoon. Morning commuters can expect temperatures in the upper 50s throughout most of Tampa Bay, according to the National Weather Service. Bu...
Published: 04/18/18
Dreaded ‘cone of uncertainty’ will shrink for the coming hurricane season

Dreaded ‘cone of uncertainty’ will shrink for the coming hurricane season

The National Hurricane Center plans to shrink the dreaded "cone of uncertainty" during the upcoming season based on an improving forecast record.The Miami-based center made the announcement Monday, along with a series of other changes intended to imp...
Published: 04/17/18
Forecast: Clear skies, abundant sunshine ahead for Tampa Bay

Forecast: Clear skies, abundant sunshine ahead for Tampa Bay

Tampa Bay will be warming up today and by the afternoon clear skies and sunshine promise ideal conditions without an abundance of humidity.But Tuesday morning started a little chilly with temperatures in upper 50s before sunrise. By afternoon, temper...
Published: 04/17/18
Forecast: Cool and windy, a day after tornado touches down in St. Petersburg

Forecast: Cool and windy, a day after tornado touches down in St. Petersburg

TAMPA — Now that Sunday’s powerful front — which actually spawned a tornado and several reported waterspouts — has moved out of Tampa Bay, the start of the work week brings sunny skies, but much cooler temperatures.This comes a day after the front ge...
Published: 04/16/18
Forecast: Tornado watch expanded to all counties in Tampa Bay

Forecast: Tornado watch expanded to all counties in Tampa Bay

ST. PETERSBURG — A tornado watch is in effect in every county surrounding Tampa Bay, and the region can expect thunderstorms and strong winds Sunday, which could make water activities dangerous.With a high of 83 degrees, the morning should be cloudy ...
Published: 04/15/18
Forecast: Warm, pleasant weekend for Tampa Bay before severe storms arrive Sunday

Forecast: Warm, pleasant weekend for Tampa Bay before severe storms arrive Sunday

The Tampa Bay area’s recent run of abundant sunshine and clear skies will extend into the weekend, but it will come to a screeching halt when severe weather sweeps in on Sunday morning.The National Weather Service has issued a severe thunderstorm war...
Published: 04/13/18
Hurricane names Harvey, Irma, Maria and Nate being retired

Hurricane names Harvey, Irma, Maria and Nate being retired

MIAMI — The names of four deadly hurricanes that slammed parts of the United States, Central America and the Caribbean last year are being retired.The National Oceanic and Atmospheric Administration announced Thursday that hurricane names Harvey, Irm...
Published: 04/12/18
Forecast: Pleasant sunshine into weekend for Tampa Bay, but Sunday thunderstorms ahead

Forecast: Pleasant sunshine into weekend for Tampa Bay, but Sunday thunderstorms ahead

Today should be a little warmer and a bit drier than Wednesday as Tampa Bay continues to enjoy a mostly sunny end of the week.After a few intense thunderstorms on Tuesday left little humidity around the bay area, Thursday should see a perfectly dry, ...
Published: 04/12/18